Wastewater FOG is produced by, for example, meat fats in food scraps, cooking oil, shortening, lard, butter and margarine, gravy, and food products such as mayonnaise, salad dressings, and sour cream. Wastewater from food source and food service facilities such as restaurants, processing plants, cruise lines and cargo ships, factories, garages, hotels, and casinos are often referred to as “gray water”. When gray water passes through sewer systems. FOG accumulates inside the pipes eventually restricting the flow in the pipes with the potential of causing untreated wastewater to back up into businesses and homes, resulting in high costs for cleanup and restoration, FOG, discharged into septic systems and drain fields can cause malfunctions, resulting in more frequent tank pump-outs and other expenses. Additionally, manholes can overflow into parks, yards, streets, and storm drains, allowing wastewater to contaminate local waters, including drinking water.
Exposure to untreated wastewater is a public-health hazard. Every year, communities spend significant sums unplugging or replacing grease-blocked pipes, repairing pump stations, and cleaning up costly and illegal wastewater spills. If a blockage can be attributed to a particular business, these communities may charge the business for the repair of the sewer pipes and the spill cleanup. In addition, communities often add a surcharge to wastewater bills if a business exceeds a specified discharge limit. These expenses can be significant.
In response, businesses attempt to reduce their FOG discharge through the use of, for example, grease traps. However, it is not practical to pump grease traps on a continual basis. Even if a grease trap is pumped on a monthly or weekly basis, in that time, significant portions of the grease will break down and turn septic. Not only does the grease have an offensive smell, but it will sink and pass out of the grease trap adding to the BOD (Biochemical Oxygen Demand) at the local sewer plant or contaminate and foul sand mounds or fields of on lot systems.
With the ever increasing cost of petroleum based fuel, biodiesel fuel is taking a more prominent role. For purposes of this application, biodiesel fuel refers to a diesel-equivalent processed fuel derived from biological sources such as mono-alkyl esters of long chain fatty acids derived from vegetable oils or animal fats. Biodiesel may be used as a pure fuel or blended with petroleum in any percentage. FOG removed from gray water can serve as an important and easily obtained biological source for the production of biodiesel fuel, thereby reducing dependence on fossil fuels while simultaneously reducing stress on public and private sewage systems. FOG is also used in the manufacture of cosmetics, animal feeds and detergents.
Known FOG removal systems such as those disclosed in U.S. Pat. Nos. 5,030,357; 4,268,396; and 4,051,024, assigned to Lowe Engineering, Friedens, Pa. and U.S. Pat. Nos. 6,878,270; 6,800,195; and 5,133,881 assigned to Thermaco, Inc., Asheboro, N.C. utilize a polyethylene revolving wheel and a wiper blade with polyethylene scraper blades, to remove FOG, which has an affinity for polyethylene. One significant disadvantage of such systems is that the wheel and blades as taught need continuous maintenance and replacement.
Accordingly, there is still a continuing need for improved FOG removal and collection system designs. The present invention fulfills this need and further provides related advantages.